Quarterly accession lists; beginning with Apr. 1893, the bulletin is limited to "subject lists, special bibliographies, and reprints or facsimiles of original documents, prints and manuscripts in the Library," the accessions being recorded in a separate classified list, Jan.-Apr. 1893, a weekly bulletin Apr. 1893-Apr. 1894, as well as a classified list of later accessions in the last number published of the bulletin itself (Jan. 1896)

By covering both administrative and non-administrative aspects of the postal network, this four-volume reset edition shows how this system was part of a larger network which included different modes of transport and communication (steamboats, railroads, telegraphs) as well as political parties (the Democrats, Whigs and Republicans).